For beginners an armature can seem complicated and overwhelming not knowing where to begin. This is a simple system that works quite well and can make an armature in a relatively short amount of time (usually 30 minutes for a 12" armature!)
There are some clays out there that are self-supporting and therefore do not require they use of a support armature. These materials are clay/wax hybrids that are light in weight and fairly rigid when cool like Castilene, which will be covered in another segment.
Step 1: PROPORTIONS
Also a child will be quite different in proportion to an adult& so on and so forth. Proportion can make a figure more or less heroic according to how many heads tall he/she is. For our purposes proportions are measured by using the head as the unit of measurement. From this unit we can find the measurements for the rest of the body. The average human being is 7 1/2 heads tall meaning that if you were to divide the person using the measurement of their head you would find that it would fit 7 1/2 times their body in height. From this there are other measurements that we can find but for the time being this is really the most important aspect you need to understand.
For sculpting you will find that 7 1/2 heads tall, although correct, can make a figure reduced to scale look a little dumpy. This is simply an illusion caused by the fact that you are sculpting something at a reduced scale from the real thing. This is especially true for female figures. In fact you can extend the legs on female figures a little to make sure they look graceful and elegant. In the end though proportion comes down to personal tastes so once you learn how proportion works you can then modify it to achieve the results that most appeal to you.